refactor: rename RDReaderView -> RDEpubReaderView, update pod config and docs

- Rename source module from RDReaderView to RDEpubReaderView
- Move all source files from Sources/RDReaderView/ to Sources/RDEpubReaderView/
- Update podspec: RDReaderView.podspec -> RDEpubReaderView.podspec
- Update Podfile, demo project, and CocoaPods config for new pod name
- Delete old RDReaderView pod support files from ReadViewDemo/Pods
- Add new RDEpubReaderView pod support files
- Update documentation (API ref, architecture, UML, conventions, etc.)
- Add FixedLayoutRotationTests
- Update .gitignore: exclude .DS_Store, manual unpack backups, _ssoft-output

.gitignore

@@ -6,3 +6,21 @@ xcuserdata/
 .artifacts/
 .deriveddata/
 .swift-module-cache/
+
+# This repository checks in the Demo Pods project. Keep generated files for the
+# local RDEpubReaderView pod visible even when a global gitignore excludes Pods.
+!ReadViewDemo/Pods/
+!ReadViewDemo/Pods/Local Podspecs/
+!ReadViewDemo/Pods/Local Podspecs/RDEpubReaderView.podspec.json
+!ReadViewDemo/Pods/Target Support Files/
+!ReadViewDemo/Pods/Target Support Files/RDEpubReaderView/
+!ReadViewDemo/Pods/Target Support Files/RDEpubReaderView/**
+
+# macOS system files
+.DS_Store
+
+# Local backup directories
+*手动解包备份*
+
+# AI tool output
+_ssoft-output/